Fix sorting input typing

src/utils/sort.ts

@@ -79,8 +79,16 @@ export function createGetSortQueryVariables<
 >(
   getSortQueryField: GetSortQueryField<TUrlField, TSortField>
 ): GetSortQueryVariables<TSortField, TParams> {
-  return (params: TParams) => ({
+  return (params: TParams) => {
+    const field = getSortQueryField(params.sort);
+
+    if (!!field) {
+      return {
         direction: getOrderDirection(params.asc),
-    field: getSortQueryField(params.sort)
-  });
+        field
+      };
+    }
+
+    return undefined;
+  };
 }